Echoing what others are saying

 

Echolalia is an obscure linguistic term used when referring to the automatic repetition of what has just been said. Although this usage is found only in conversation, it can, and does, occur in every sentence classification.
My 1899 Public School Grammar divides sentences into three categories: assertive, interrogative and imperative. Things change. I was taught a fourth type — exclamatory.
The echoing of words is found in however many kinds of sentences we recognize. In a statement (assertive sentence), Marc might say, “Joe lost his job,” and Phil might answer, “Joe lost his job?”
In a question (interrogative sentence): “Have you seen my jacket?” “Have I seen your jacket?”
In a directive sentence (imperative): “Turn on the TV.” “I’ll turn on the TV.”
In an exclamation: “What a splendid view!” “Yes. What a splendid view!”
Everyone uses echolalia sometimes, and it’s also identified as an element of the speech handicap associated with both autistic and language-delayed children. As well, recent studies link echolalia, sometimes called echoism, to such adult conditions as the onset of dementia.
At the same time, it’s deliberately used as a way of gaining time by those having no speech problems. Cambridge calls this tactic, “intelligent echoes,” and goes on to say, “If we find ourselves out of our depth in a conversation, it is possible to convey an intelligent impression by occasionally echoing parts of what other people are saying.”
The word echoism was coined in 1880 by J.A.H. Murray, the famous first editor of the Oxford English Dictionary (OED).
That dictionary’s primary definition of echoism refers to the echoing of real-life sounds. For example, “splash” imitates the sound a liquid makes when it strikes something. We’re not usually taught to call this sound echoism or echolalia. We’re told it is onomatopoeia. Murray sought a simpler, more descriptive word. 
The OED’s second definition is, “An expression that echoes or alludes to another.”
Both echoism and echolalia owe their origins to the wood nymph Echo, a character from Greek myth. Mythology tells us Echo was in love with an egotistical youth named Narcissus, who couldn’t return her devotion because he loved only himself. It didn’t help that Echo was a compulsive talker who always had to have the last word.
Then one day, Echo angered the goddess, Juno, who punished her by taking away her ability to converse. Forever after, Echo was able to say only what someone else had just said. In frustrated sorrow, Echo fled to the mountains where she died in isolation. But her voice remains to this day, and she still always has the last word.
As for Narcissus, he fell passionately in love with his own reflection in a pool of water. Although nothing could come of this obsession, he knelt, staring at his image, until he died of grief. At once, a flower sprang up where he had been rooted for so long. We call that flower a narcissus.
Echolalia first appeared in English in the 1880s. It is a combination of echo (sound) and lalia (speech).